1. Technical Field
The present invention relates to a wearable electronic apparatus including a measurement unit that measures a location, etc.
2. Related Art
In related art, a device that measures an accumulated travel distance using a GPS has been known (for example, Patent Document 1 (JP-A-2003-322545)). The device is used as a wristwatch-type wearable electronic apparatus having a location measurement function of measuring a current location on the earth and called “running watch”, “training watch”, “runner's watch”, or the like. The electronic apparatus has a clock, a GPS receiver, an arithmetic unit, and a memory medium. When a user starts measurement of the location in running, the electronic apparatus automatically and continuously stores location measurement information including periodically measured latitude and longitude. Further, the location information or the like during running stored in the electronic apparatus is analyzed by an external device including a personal computer and used for display of the trajectory of running on a map (map display) and graphical display of changes from the start to the end of the running by computation of parameters including paces and pitches. The user may realize efficient training using the map display and the graphical display.
In wearable electronic apparatuses having the location measurement function such as a running watch, one of the most important requirements is thinness and lightness not to be a burden in running, i.e., “reduction in size and weight”. However, there is a trade-off between the reduction in size and weight and the amount of mounting of the memory medium such as an IC memory and the size of a battery (i.e., capacity) that can be mounted. Accordingly, in a known running watch or the like, the data memory capacity and the battery duration are sufficient for running at relatively short distances and short times, but liable to be insufficient for running taking longer required time and long-distance running including a full marathon.
Further, in location measurement using the GPS or the like, it is not necessarily that the location is always measured with accuracy due to various environment factors. If the user linearly moves, the location indicated by the measurement result may fluctuate to right and left or, sometimes the location is measured as if the user has jumped high. On this account, if the location information of the memory points stored in the running watch or the like is used for map display without change, a trajectory more zigzag than the actual running trajectory, and sometimes largely deviating from the actual trajectory may be drawn. Furthermore, when the distance is computed from the displacement of the location of the memory point, an error relative to the actual travel distance occurs.